Modular steel panel for walls: life cycle environmental impact, life cycle cost, and potential for material circulation

The impacts of civil construction are widely recognized and justify the transition from a linear to a circular economy. Furthermore, with building users increasingly demanding greater adaptability, strategies such as modularity and flexibility to adapt to changing uses are being discussed. Modular wall panels allow quick installation and have the potential for disassembly, refurbishment, reuse, and recycling. We evaluate a modular steel panel system in two Brazilian case studies through life cycle assessment (LCA), life cycle cost (LCC), and building circularity index (BCI). The study applies the circular reuse and remanufacture, recycling, and life extension strategies for internal and external walls. For the external panel, the life extension strategy (SE02) stands out positively in all impact categories, with the lowest environmental impact and costs. However, the SE02′s BCI does not have the best result. The second best option is reuse (SE03), with the highest percentage of circularity. Furthermore, the differences between SE02 and SE03 are reduced in several impact categories, and the sensitivity analysis (transport, damage, and the number of reuses) shows that the differences could be even smaller. For the internal panel, life extension (SI02) and reuse (SI03) scenarios are the best options. Recycling (SI04) has the highest environmental impact and the best potential for circularity. BCI communication must be aligned with LCA and LCC, such that an increase in circularity is accompanied by a decrease in environmental impacts or with infeasible costs, especially for developing countries.